Not applicable.
Not applicable.
The present invention relates to devices for the artificial insemination of livestock in general, and more particularly to those for introducing boar semen or embryos into a sow uterus in particular.
Artificial insemination techniques have been employed in swine breeding not only for the improved control over breeding characteristics which they offer, but also for the increased efficiency and improved fertility which may be obtained.
In the conventional approach, boar semen is first collected, tested and packaged. This collection may take place within the same facility in which the sows reside, or semen may be collected at a remote location and transported to the place of insemination. When a particular sow is determined to be in heat, a technician introduces the distal foam or spiral end of an insemination catheter into the cervix of the sow. A quantity of boar semen is then introduced through the catheter into the uterus of the sow. The original collected semen will usually be diluted with an extender. To effectively inseminate the sow, and achieve the maximum desirable litter size, sperm cells must travel through the uterus into the coiled uterine horns and then down the oviduct to reach the ova so that fertilization can take place. Due to the extended length of travel, a large quantity of semen must be used, on the order of 70-75 ml, containing 2.5 to 5 billion sperm cells.
Surgical experiments have shown that if the boar semen can be inserted into closer proximity to the uterine horns, a reduced number of sperm cells and semen volume may be used. Smaller insemination dosages would reduce the levels of semen collection required, as well as reducing packaging, shipping, and storage costs per dose of semen or embryos. Moreover, in some cases lower quantities of sperm cells may be available, such as when using sexed semen. The sorting of boar sperm cells on the basis of gender takes a long time, for example, about 100 million cells per hour. For a conventional dosage of 3 billion sperm cells, the sexing process would take about 30 hours, yielding a very high cost per insemination. If a reduced dosage of 500 million sperm cells could be employed, the time to perform the sexing is greatly reduced. Or even where the total volume of semen is not reduced, semen of lower fertility, such as frozen semen, may be employed with higher effectiveness. However, surgical insemination is not a practical production technique. The sow reproductive tract is fairly delicate, and extremely prone to damage when subjected to the intrusion of an insemination catheter. The interdigitating processes of the cervix may impede movement of the catheter. An inseminator in haste could potentially push through the cervical wall when trying to pass around the interdigitating processes. Even if such injuries are so minor as to not cause serious harm to the sow, there may be a release of blood into the uterus. Blood however, is incompatible with sperm, and can kill the sperm cells. Moreover, sow insemination is most frequently carried out by personnel who are not veterinarians or specialists. It is therefore desirable that any insemination device be easy to use after a minimum of training. By the same token, transfer of embryos would be facilitated if the embryo can be placed within the sow uterus.
Conventional intrauterine insemination catheters have been formed with a molded plastic blunt end which is attached by a press-fit or adhesive to a narrow flexible tube. However, these molded parts will usually have a parting line, or a joint where they are connected to the tube. This sharp edge is prone to catching on the cervical interdigitating processes or uterine folds, and readily causing injury. The narrow ends or tips of various conventional intrauterine insemination catheters are formed so that puncturing the uterine wall or cervical wall is possible.
What is needed is a device for introducing biological material into a sow which permits embryos or boar semen to be introduced more closely to the uterine horns without injury to the sow.
The catheter assembly of this invention is for the introduction of biological material into the uterus of a sow, and may alternatively be used for sow insemination or for introduction of swine embryos into the uterus of a sow. The assembly has an internal flexible plastic catheter with a tubular body and an integrally formed protruding head. An axial channel extends from the outside of the sow through the internal catheter and discharges frontwardly of the head. The internal catheter is received within an exterior catheter which has an axial channel which is larger in diameter than the tubular body of the internal catheter, but which is smaller in diameter than the internal catheter head. During introduction of the assembly into the uterus of a sow, the internal catheter head is preferably withdrawn within the forward portion of a resilient tip forming a part of the exterior catheter. The internal catheter head is thereby shielded from clogging until the forward end of the assembly has been positioned as deep as possible within the sow""s cervix. At that time the flexible internal catheter is advanced through the tip and into the uterus. The rounded head on the internal catheter is then steered upwards through the external uterine bifurcation into one or the other of the sow""s uterine horns. Semen or embryos are then introduced through the axial cavity within the internal catheter and discharged into the uterine body or horn. The cleanliness of the internal catheter prior to discharge of fluid into the uterus may be further preserved by providing the tip on the outer tube with a protective flap which is not penetrated until the internal catheter is advanced past the tip. The internal catheter axial channel may have a constricted portion within the head, permitting semen or embryo containing straws to be positioned therein, for discharge of the contents by a flexible stylette.
It is an object of the present invention to provide a catheter for introducing boar semen or embryos into a sow which is less prone to damaging the tissue in the uterus or the cervix of the sow.
It is a further object of the present invention to provide a sow intrauterine catheter which can be economically produced.
It is an additional object of the present invention to provide a disposable catheter for use in swine Al techniques which can be manipulated with reduced risk of injury to the animal.
It is also an object of the present invention to provide a catheter for sow AI techniques which can be hygienically retained within an outer catheter until the outer catheter is fully inserted into the animal.
It is yet another object of the present invention to provide a catheter assembly which allows straw-packaged biological material to be employed.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.